As I write this note in July 2017, the future of the Affordable Care Act remains unclear. Republicans have not abandoned their aim to “repeal and replace” the ACA, yet they have so far been unable to coalesce around a feasible alternative. Whatever the outcome of the current legislative struggle, ideologically charged debates over how best to improve the affordability, efficiency, equity, and political acceptability and sustainability of governmental interventions in the health care sector will continue, both in the United States and in other advanced democracies. The fundamental challenges of health care reform won't go away.

Given the hard realities of politics and economics, is there room for innovation in health policy? Can policy reformers alter long-standing patterns of resource allocation, market design, and political engagement, or are these patterns largely immune to change? Under what circumstances can health policy making...